The present invention relates in general to a melting and dispensing apparatus for solid materials such as tar, asphalt, and the like, and more particularly, to such an apparatus having a flexible discharge line adapted for dispensing, at various remote locations, such material being supplied from a source thereof in a heated, fluid condition, while maintaining the material in its fluid condition within the discharge line during periods of intermittent non-use of the apparatus.
In the resurfacing of roadways, it is required that cracks and joints in the surface of the roadway be filled prior to the resurfacing operation with tar or asphalt supplied to these voids in a heated, fluid condition. In order to economize the filling of these voids and to reduce the manual labor requirement, the prior art has recognized the desirability of providing a flexible discharge line, which can supply asphalt in a heated, fluid condition from an asphalt melting apparatus to various remote locations along the roadway. Commercial asphalt melting apparatus presently in use are constructed of a jacketed melting kettle using an oil heating medium within the kettle jacket to heat the solid asphalt to a fluid condition. The oil heating medium is directly heated within the jacket by an external fuel burner, typically using propane fuel. A flexible metal discharge hose is provided for dispensing the asphalt from the kettle in a fluid condition to the various remote locations by the manual manipulation of the discharge hose.
However, the conventional apparatus suffers from a number of notable disadvantages. For example, and most significantly, it is required that a continuous flow of asphalt in a heated fluid condition be supplied through the discharge hose to prevent its solidification therein. Thus, when an operator intermittently uses the apparatus, for example, when taking a break, during lunch, etc., the asphalt within the discharge hose often solidifies during this period, particularly in colder environments. In order to then use the apparatus for dispensing asphalt, the solidified asphalt within the discharge hose must be heated once again to a fluid condition, often by means of a blowtorch. In addition to this heating operation being time-consuming and labor intensive, the heat stress applied to the flexible metal discharge hose by a blowtorch seriously shortens its life span and/or causes the failure thereof, thereby necessitating its frequent replacement along with its associated economic loss and labor intensive requirement.
In U.S. Pat. No. 1,924,636, there is disclosed an asphalt melting apparatus adapted for use in filling cracks and joints in roadways with tar or tar compounds. The apparatus is constructed of a kettle directly heated by an underlying fuel burner, which are both rotationably mounted to a support structure. The asphalt, in a heated fluid condition, is discharged through a jacketed rigid conduit to the location of the joint or crack to be filled. A portion of the hot flue gases from the fuel burner are directed into the jacket surrounding the rigid conduit to prevent the solidification of the asphalt therein. During use, in order to manipulate the discharge end of the rigid conduit, it is required that the entire kettle and fuel burner be rotated about the underlying support structure. This manipulation requires the use of a complicated rotating assembly, which is not only expensive to manufacture, but which, due to the high temperature of its environment, is subject to a shortened life span. Further, the necessity of having to rotate the asphalt kettle and underlying fuel burner, as one can appreciate, is both dangerous to the operator and imposes severe limitations on the ability to position the discharge end of the rigid conduit at various remote locations. As the rigid conduit can only be rotated about the support structure, in order to position the discharge end at other than a circumferential position, it is required that the entire support structure, including asphalt kettle and fuel burner, be continuously moved in a random manner along the roadway. It can therefore be appreciated that this necessity of having to push the entire asphalt melting apparatus, as well as having to simultaneously rotate the asphalt kettle and fuel burner in order to dispense the asphalt at pre-selected locations, is both awkward, cumbersome, and highly undesirable.
Accordingly, it can be appreciated that there is an unsolved need for a portable, self-contained, asphalt melting and dispensing apparatus, which allows for the dispensing of asphalt in a heated fluid condition at remote locations independent of the location of the source of the asphalt, and which maintains the asphalt in a heated fluid condition within the discharge line during intermittant non-use of the apparatus.